Method for scroll bar control on a touchpad

ABSTRACT

In a method for scroll bar control on a touchpad, the fingers touching on the touchpad are detected to start up and terminate a scroll bar control function. In the scroll bar control function, the movement of the finger or fingers touching on the touchpad is detected for scrolling on a window, and the vertical distance and the horizontal distance of the movement are evaluated for determining the scrolling amount of a vertical scroll bar or a horizontal scroll bar of the window.

FIELD OF THE INVENTION

The present invention is related generally to a scroll bar operatingmethod and particularly to a method for scroll bar control on atouchpad.

BACKGROUND OF THE INVENTION

Recently, due to the advantages of simple, light and low cost, thetouchpad has been widely applied in various electronic products toreplace the conventional input devices, for example the computer mouse.A method and apparatus for scroll bar control is proposed by U.S. Pat.No. 5,943,052 to Allen et al., to define scroll regions on a touchpadfor scrolling the scroll bars of a window. Specifically, as shown inFIG. 1, on a touchpad 10 there are a block 12 to be defined for cursorcontrol region, a block 14 to be defined for vertical scroll region, anda block 16 to be defined for horizontal scroll region. When a user is tomove a cursor, he needs to put his finger in the cursor control region12 first, and then to move his finger in the cursor control region 12 tocontrol the movement of the cursor. When a user is to scroll a window inthe vertical direction, he is requested to put his finger in thevertical scroll region 14 first, and then to vertically move his fingerin the vertical scroll region 12 to control the vertical scroll bar ofthe window. Similarly, to scroll a window in the horizontal direction, auser is requested to put his finger in the horizontal scroll region 16first and then to horizontally move his finger in the horizontal scrollregion 16. However, defining the vertical scroll region 14 and thehorizontal scroll region 16 will reduce the area of the cursor controlregion 12, and therefore have the operations in the cursor controlregion 12 more difficult. Moreover, the vertical scroll region 14 andthe horizontal scroll region 16 cannot be enabled to use at a same time.Further, each time to switch between the cursor control function and thescroll bar control functions, for example from the cursor controlfunction to the vertical scroll bar control function or from thevertical scroll bar control function to the horizontal scroll barcontrol function, the user is necessary to have his finger leaving thetouchpad 10 from the current region first and then touching on thetouchpad 10 in another region again, to terminate the current controlfunction and to start up the next control function. For example,slipping the finger on the touchpad 10 from the cursor control region 12to either the vertical scroll region 14 or the horizontal scroll region16 will not enable any scroll bar control functions. Moredisadvantageously, to avoid the finger to put in a wrong region whenswitching between difference control functions, the user needs to movehis eyes from the monitor to the touchpad 10 to ensure the positionwhere his finger is touching on again and again.

On the other hand, a method is proposed by U.S. Pat. No. 5,825,352 toBisset et al., by sensing the number of fingers landing on a touchpad toemulate mouse buttons and mouse operations. However, this art cannotprovide any scroll bar control functions by operating on a touchpad.

Therefore, it is desired a method using multiple fingers for scroll barcontrol on a touchpad.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a method for scrollbar control on a touchpad.

In a method for scroll bar control on a touchpad, according to thepresent invention, the fingers touching on the touchpad are detected,and if the number of the fingers is equal to or more than a firstthreshold, a scroll bar control function starts up. In the scroll barcontrol function, the movement of the finger or fingers touching on thetouchpad is detected, and the vertical distance and the horizontaldistance of the movement are evaluated for determining the scrollingamount of a vertical scroll bar or a horizontal scroll bar of a window.Moving the fingers to leave the number of the fingers touching on thetouchpad less than a second threshold will terminate the scroll barcontrol function.

Alternatively, the difference between the vertical distance and thehorizontal distance is evaluated to determine the scrolling amount ofthe vertical scroll bar or the horizontal scroll bar. If the verticaldistance is larger than the horizontal distance over a reference, thevertical scroll bar of the window is scrolled by a scrolling amountproportional to the difference. If the horizontal distance is largerthan the vertical distance over the reference, the horizontal scroll barof the window is scrolled by a scrolling amount proportional to thedifference.

Alternatively, if the vertical distance is larger than the horizontaldistance over a reference, the vertical scroll bar of the window isscrolled by a scrolling amount proportional to the vertical distance,and if the horizontal distance is larger than the vertical distance overthe reference, the horizontal scroll bar of the window is scrolled by ascrolling amount proportional to the horizontal distance.

Preferably, once the scroll bar control function starts up, the methodaccording to the present invention allows a user to leave only a fingerslipping on the touchpad to scroll a vertical or horizontal scroll bar.

By detecting the number of fingers touching on the touchpad to switchbetween different control functions, the method according to the presentinvention does not need to define vertical and horizontal scroll regionson a touchpad, and does not request the user to move his eyes to thetouchpad all the time in use. Moreover, the vertical and horizontalscroll bars may be simultaneously operated by only a movement of fingeror fingers on a touchpad.

BRIEF DESCRIPTION OF DRAWINGS

These and other objects, features and advantages of the presentinvention will become apparent to those skilled in the art uponconsideration of the following description of the preferred embodimentsof the present invention taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 shows a conventional touchpad serving as a computer mouse;

FIG. 2 shows a touchpad serving as an input device communicated with ahost system according to the present invention;

FIG. 3 shows a flowchart of a method for scroll bar control on thetouchpad of FIG. 2 according to the present invention;

FIG. 4 shows several fingers touching on the touchpad of FIG. 2 to startup a scroll bar control function;

FIG. 5 is a diagram of slipping the fingers on the touchpad of FIG. 2upward and rightward to scroll on a window;

FIG. 6 is a diagram of slipping the fingers on the touchpad of FIG. 2 inan arbitrary direction to scroll on a window;

FIG. 7 is a diagram of leaving only a finger touching on the touchpad ofFIG. 2 to scroll on a window; and

FIG. 8 is a diagram of slipping a finger on the touchpad of FIG. 2 forscrolling on a window.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 shows a touchpad 20 serving as an input device communicated witha host system according to the present invention, on which a finger 22is slipping in arbitrary directions for cursor movement control on awindow of an application running on the host system. FIG. 3 shows aflowchart of a method for scroll bar control on the touchpad 20according to the present invention. In step 30, it is detected if thefingers (number N) touching on the touchpad 20 is equal to or more thana threshold TH for example two, and if it is (N≧TH), go to step 32 for astart-up of a scroll bar control function, otherwise go to step 34 forother or no operations. When a user desires for scroll bar control onthe touchpad 20, the only thing to do is to put his one or more otherfingers 24 on the touchpad 20, as shown in FIG. 4, such that the fingers22-24 touching on the touchpad 20 are equal to or more than thepredetermined threshold TH. Once the fingers 22-24 touching on thetouchpad 20 are detected equal to or more than the threshold TH, thetouchpad 20 is switched from the cursor control function to the scrollbar control function. After switching to the scroll bar controlfunction, as shown in FIG. 5, it is detected the movement of the fingers22-24 on the touchpad 20 in step 36. When the fingers 22-24 slipping onthe touchpad 20, the distance of the movement will be evaluated in step38, for example a distance A of an upward movement or a distance B of arightward movement, as shown in FIG. 5, and then a signal is generatedto send to the host system for scrolling on the window, in which thescrolling amounts of the vertical and horizontal scroll bars of thewindow are determined with the distances A and B respectively,preferably in a proportional manner. In addition to moving in thevertical and horizontal directions as shown in FIG. 5, the fingers 22-24may be slipping on the touchpad 20 in an arbitrary direction {rightarrow over (a)}, as shown in FIG. 6, and the scrolling direction and thescrolling amount of the window may be determined by various schemes, forexample illustrated by three embodiments in the following:

First Embodiment of Scroll Bar Control

Referring to FIG. 6, the vertical component A and the horizontalcomponent B of the distance C of the movement in the direction {rightarrow over (a)} are first evaluated, and in the signal sent to the hostsystem for scroll bar control, the vertical and horizontal scroll barsof the window are scrolled simultaneously, with a vertical scrollingamount proportional to the distance A and a horizontal scrolling amountproportional to the distance B.

Second Embodiment of Scroll Bar Control

Referring to FIG. 6, the vertical component A and the horizontalcomponent B of the distance C of the movement in the direction {rightarrow over (a)} are first evaluated, and the difference D between thedistances A and B are further evaluated. If the vertical distance A islarger than the horizontal distance B over a reference R, i.e.,D=(A−B)>R, then the vertical scroll bar of the window is scrolled, andthe scrolling amount of the vertical scroll bar is proportional to thedifference D. On the contrary, if the horizontal distance B is largerthan the vertical distance A over the reference R, i.e., D=(B−A)>R, thenthe horizontal scroll bar of the window is scrolled, and the scrollingamount of the horizontal scroll bar is proportional to the difference D.

Third Embodiment of Scroll Bar Control

Referring to FIG. 6, the vertical component A and the horizontalcomponent B of the distance C of the movement in the direction {rightarrow over (a)} are first evaluated, and the distances A and B arecompared to each other. If the vertical distance A is larger than thehorizontal distance B over a reference R, i.e., (A−B)>R, then thevertical scroll bar of the window is scrolled by a scrolling amountproportional to the vertical distance A. On the contrary, if thehorizontal distance B is larger than the vertical distance A over thereference R, i.e., (B−A)>R, then the horizontal scroll bar of the windowis scrolled by a scrolling amount proportional to the horizontaldistance B.

Referring back to FIG. 3, in step 40, the scroll bar control functionwill be terminated if the fingers touching on the touchpad 20 are equalto or less than a threshold for example zero. In the case of a zerothreshold, all the fingers 22-24 leaving the touchpad 20 will terminatethe scroll bar control function. After terminating the scroll barcontrol function, if a finger 22 is touching on the touchpad 20 again,the touchpad 20 will be switched to the cursor control function, whileif several fingers 22-24 equal to or more than the threshold TH aretouching on the touchpad 20 again, the touchpad 20 will be switched backto the scroll bar control function as illustrated in FIG. 3. In anotherembodiment, after the start-up of a scroll bar control function byseveral fingers 22-24 touching on the touchpad 20 as shown in FIG. 4,the finger or fingers 24 may be removed from the touchpad 20 for leavingonly the finger 22 still touching on the touchpad 20 as shown in FIG. 7,and then slipping the finger 22 on the touchpad 20 for scrolling on awindow as shown in FIG. 8.

While the present invention has been described in conjunction withpreferred embodiments thereof, it is evident that many alternatives,modifications and variations will be apparent to those skilled in theart. Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and scopethereof as set fourth in the appended claims.

1. A method for scroll bar control on a touchpad, comprising the stepsof: detecting if a number of fingers touching on the touchpad is equalto or larger than a threshold, for starting up a scroll bar controlfunction; and in the scroll bar control function, detecting a movementof one or more fingers slipping on the touchpad for scrolling on awindow accordingly.
 2. The method according to claim 1, wherein thethreshold is two.
 3. The method according to claim 1, further comprisingcontinuing the scroll bar control function during the fingers touchingon the touchpad is not less than a second threshold.
 4. The methodaccording to claim 1, further comprising terminating the scroll barcontrol function once the fingers touching on the touchpad are equal toor less than a second threshold.
 5. The method according to claim 4,wherein the second threshold is zero.
 6. The method according to claim1, further comprising evaluating a vertical distance and a horizontaldistance of the movement for scrolling a vertical scroll bar and ahorizontal scroll bar on the window, respectively.
 7. The methodaccording to claim 1, further comprising evaluating a vertical distanceand a horizontal distance of the movement for scrolling a verticalscroll bar on the window if the vertical distance is larger than thehorizontal distance over a reference, or scrolling a horizontal scrollbar on the window if the horizontal distance is larger than the verticaldistance over the reference.
 8. The method according to claim 7, furthercomprising determining a scrolling amount for the vertical scroll bar inproportion to a difference between the vertical distance and thehorizontal distance.
 9. The method according to claim 7, furthercomprising determining a scrolling amount for the vertical scroll bar inproportion to the vertical distance.
 10. The method according to claim7, further comprising determining a scrolling amount for the horizontalscroll bar in proportion to a difference between the horizontal distanceand the vertical distance.
 11. The method according to claim 7, furthercomprising determining a scrolling amount for the horizontal scroll barin proportion to the horizontal distance.